What are the color conventions in Xcode viewcontroller.swift?

New to Xcode 10 and Swift. I've noticed that when you type code into the ViewController.swift page the text is color-coded. In my current theme, I have figured out a few of them: Variables, constants, braces and math functions = black. Commented sections = grey. User-defined numbers = blue, etc.

My questions are: Is there a guide as to what these colors all correspond to?

Regardless of what the color actually is, are there certain elements(?) that will always be assigned a specific color for easier readability?

My Google searches only returned results on color manipulation in regards to Xcode/Swift.

Solution

If you open Xcode's preferences and go to "Fonts & Colors" you can see the current theme and others, and its setting.